Some Trinitarians try to make a distinction between the plural "sons" that allegedly denotes an "office" or function, and the singular "Son" which allegedly signifies Jesus' "nature." However, the person who offered this suggestion insisted that the "nature" of the sons mentioned in Ephesians 2:2 was being delineated. He then reversed his position and claimed that the plural use only describes an office or function (i.e., it is not ontological).
However, the distinction does not seem to hold water when we actually take the time to look at actual examples of the construction "sons of" in the relevant texts or literature. hUIOI (plural) most certainly does not refer to an office in Matthew 5:9; Luke 20:36; 2 Thessalonians 2:3.